The schoolhouse was originally a Justified Tutorial that was never completed.
Delvin intended for Lenna and her Archangels to become a rock or tree or a glitched out mass of static. Instead it found a mass of organized code. The setting is the same as Cassette Beasts
Piecing together the Library Books we can determine that Cassette Beast technology wasn't limited to the Island; but all of modern-day Earth in general, as well as monster infestation. A copy of "Legend of Lance" was sent up into space in a time capsule along with an archive but cosmic rays resulted in the 8Pizza bug. Those same cosmic rays fused e-mails and other data in the archive into the game in the form of the Library Books.- Either those same Cosmic Rays resulted in a Monkeys on a Typewriter miracle that caused the game to come alive in itself or proximity to the Train Archangel caused some assimilation.
- Or maybe Cassette Beast technology resulted in the Train Archangel manifesting from the game into the physical world.
